Participation in clinical trials (CTs) requires multiple obligations by cancer patients that can add to the burden of a cancer diagnosis and treatment. Burden, also called respondent burden, is a phenomenon that has not been adequately studied in seriously ill cancer patients enrolled in clinically based research. Subjects interpret research situations differently and may be willing to accept considerable levels of burden in relationship to the perceived benefits. Understanding the benefit-burden balance involved in the voluntary consent of human subjects is a fundamental tenet of research and important to ensure subjects have made an informed decision regarding their research participation. This application directly responds to the objectives of the PA on Research on Clinical Decision Making in Life-Threatening Illness as our study will investigate how perceptions of benefit and burden influences cancer subjects'clinical decisions to remain enrolled in CTs. Little conceptual and empirical research exists to better understand factors important in CT retention, including the perceived benefit and burden to those who have consented to participate in clinical cancer research trials. To better understand the dimensions of benefit and burden in CTs and its potential influence on retention among cancer subjects, the specific aims intend to: 1) determine what adult cancer research subjects perceive as physical, psychological, economical, social, and educational benefits and burdens in CTs;2) develop items for future use in constructing a preliminary benefit-burden measure to assess cancer subjects'decisions related to CT retention;and 3) identify the factors that influence adult cancer research subjects'perceptions of benefit and burden and retention in CTs. These aims will be met through a mixed methods two phase project using qualitative and quantitative methods. Phase I of this study will explore and generate themes about respondent benefit-burden in 30-35 cancer subjects enrolled in cancer CTs using face-to-face semi-structured interviews;and will use the findings to develop survey questionnaire items related to benefit and burden based on these themes. In Phase Two, a purposive sample of 109 cancer subjects will be surveyed so that hypotheses can be tested that relate perceptions of benefit and burden on several dimensions to retention in CTs. The investigative team assembled for this study is experienced in philosophical foundations, methodological approaches and empirical testing of ethical issues central to building knowledge about benefit and burden and retention of research participants. Study findings will support the missions of both NINR and NCI as exploring what subjects believe to be beneficial and burdensome in clinical research is a first step at identifying early subjects who are "at-risk for attrition." Early identification and pre-emptive interventions prior to encountering retention problems in cancer clinical trials may mitigate respondent burden and lead to completion of important, resource intensive clinical trials.